This disclosure relates to tube assemblies, and more particularly to tube assemblies for aerospace and gas turbine engine applications.
Tube assemblies generally include at least one fitting for fastening or joining two tubes to each other. Common types of fittings include ferrules, elbows, t-connectors and union crosses. Fittings used for joining tubes are commonly made of metal and are engaged by a locking mechanism, such as a nut. When a fitting joins two tubes, one tube mechanically attaches to an end of the fitting and the other tube usually requires a coupling device to secure to the other end of the fitting.
Fittings used in aerospace applications also typically require a locking mechanism to ensure the nut stays engaged to the fitting and does not unintentionally loosen (due to vibrations, wear or other causes). One type of locking mechanism includes a lockwire. Lockwire is a braided wire that may be connected to the fitting and to a nut and/or to another object (coupling member, tube, etc.) to prevent relative rotation. The usage of lockwire generally requires additional space, and in some cases is difficult to repair or install, making lockwire ergonomically undesirable. Moreover a break in one or more of the braids of the lockwire may allow the coupling member to disengage.